Tripartite motif-containing protein 31 confers protection against nonalcoholic steatohepatitis by deactivating mitogen-activated protein kinase kinase kinase 7.

BACKGROUND AIMS: As a global health threat, NASH has been confirmed to be a chronic progressive liver disease that is strongly associated with obesity. However, no approved drugs or efficient therapeutic strategies are valid, mainly because its complicated pathological processes is underestimated. APPROACH RESULTS: We identified the RING-type E3 ubiquitin transferase-tripartite motif-containing protein 31 (TRIM31), a member of the E3 ubiquitin ligases family, as an efficient endogenous inhibitor of transforming growth factor-beta-activated kinase 1 (mitogen-activated protein kinase kinase kinase 7; MAP3K7), and we further confirmed that TRIM31 is an MAP3K7-interacting protein and promotes MAP3K7 degradation by enhancing ubiquitination of K48 linkage in hepatocytes. Hepatocyte-specific Trim31 deletion blocks hepatic metabolism homeostasis, concomitant with glucose metabolic syndrome, lipid accumulation, up-regulated inflammation, and dramatically facilitates NASH progression. Inversely, transgenic overexpression, lentivirus, or adeno-associated virus-mediated Trim31 gene therapy restrain NASH in three dietary mice models. Mechanistically, in response to metabolic insults, TRIM31 interacts with MAP3K7 and conjugates K48-linked ubiquitination chains to promote MAP3K7 degradation, thus blocking MAP3K7 abundance and its downstream signaling cascade activation in hepatocytes. CONCLUSIONS: TRIM31 may serve as a promising therapeutic target for NASH treatment and associated metabolic disorders.

mascRNA and its parent lncRNA MALAT1 promote proliferation and metastasis of hepatocellular carcinoma cells by activating ERK/MAPK signaling pathway.

MALAT1-associated small cytoplasmic RNA (mascRNA) is a cytoplasmic tRNA-like small RNA derived from nucleus-located long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1). While MALAT1 was extensively studied and was found to function in multiple cellular processes, including tumorigenesis and tumor progression, the role of mascRNA was largely unknown. Here we show that mascRNA is upregulated in multiple cancer cell lines and hepatocellular carcinoma (HCC) clinical samples. Using HCC cells as model, we found that mascRNA and its parent lncRNA MALAT1 can both promote cell proliferation, migration, and invasion in vitro. Correspondingly, both of them can enhance the tumor growth in mice subcutaneous tumor model and can promote metastasis by tail intravenous injection of HCC cells. Furthermore, we revealed that mascRNA and MALAT1 can both activate ERK/MAPK signaling pathway, which regulates metastasis-related genes and may contribute to the aggressive phenotype of HCC cells. Our results indicate a coordination in function and mechanism of mascRNA and MALAT1 during development and progress of HCC, and provide a paradigm for deciphering tRNA-like structures and their parent transcripts in mammalian cells.

STAT1 participates in the induction of substance P expression in airway epithelial cells by respiratory syncytial virus.

PURPOSE: The regulation effect and mechanism of respiratory syncytial virus (RSV) infection on the expression of tachykinin substance P (SP) in airway epithelial cells was investigated. METHODS: The regulation of SP expression by RSV was investigated in the BEAS-2B airway epithelial cell line. RT-qPCR, immunofluorescence, and ELISA assay were used to examine the expression of the SP encoding gene TAC1, the intracellular SP protein expression, and the extracellular SP secretion. RESULTS: The mRNA expression of TAC1 and the intracellular SP protein level in BEAS-2B cells were significantly enhanced by RSV infection with multiplicity of infection (MOI) values of both 1 and 0.1 at 48 hours post infection. Heat-inactivated and UV-inactivated RSV, but not live RSV, significantly induced SP secretion in both control BEAS-2B cells and CX3CR1 receptor knockout cells without affecting the TAC1 gene expression or cell viability. RSV G protein (2-10 µg/ml) and fractalkine (10-50 ng/ml), both CX3CR1 receptor ligands, did not affect SP secretion in BEAS-2B cells. Inhibition of STAT1 phosphorylation by fludarabine (1 µM) markedly reduced the RSV-induced TAC1 gene expression and antagonized the inhibition of RSV replication by interferon-α in BEAS-2B cells. CONCLUSIONS: STAT1 participates in RSV infection-induced SP expression in airway epithelial cells.

Serum Total Bile Acid is Closely Related to the Significant Liver Injury in Patients with Non-Cholestatic Chronic Hepatitis B Virus Infection: a Cross-Sectional Study.

BACKGROUND: The relationship between non-cholestatic liver disease and total bile acid (TBA) remains obscure. The present study aimed to verify this relationship in patients with non-cholestatic chronic hepatitis B virus (HBV) infection. METHODS: A total of 922 consecutive chronic HBV infected patients with alkaline phosphatase (ALP) ≤ 1.5 upper limit of normal (ULN) and gamma-glutamyl transferase (GGT) ≤ 3 ULN were rigorously included in this cross-sectional study. Liver biopsy was performed in 53 patients and Scheuer scoring system was used to evaluate inflammation grade. G3/G4 or Child-Pugh B/C were considered to be significant liver injury. RESULTS: Compared to Child-Pugh A, TBA, total bilirubin (TBIL), ALP, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and AST to ALT ratio (AST/ALT) were significantly higher in Child-Pugh B/C, while TBIL to TBA ratio (TBIL/TBA) was significantly lower (all p < 0.001). In multivariate analysis, TBA and AST/ALT were independently correlated with Child-Pugh B/C [odds ratio (OR) = 1.04, p < 0.001; OR = 1.79, p < 0.001, respectively]. The area under the curve (AUC) of TBA (0.82) was significantly higher than that of AST (0.73, p < 0.001) and ALT (0.63, p < 0.001). Furthermore, in patients with liver biopsy, TBA was also significantly higher in G3/G4 while TBIL/TBA was significantly lower (p < 0.05). After adjusting the factors related to bile excretion, TBIL/TBA was independently associated with G3/G4 (OR = 0.89, p = 0.037). CONCLUSIONS: Serum TBA shows a close relationship with significant liver injury in chronic HBV infected patients without cholestasis. Assessment of TBA, especially in combination with TBIL/TBA, may serve as a non-invasive marker for the diagnosis of non-cholestatic hepatic damage.

Platelet count is closely associated with the severity of liver injury in patients with chronic hepatitis B virus infection: A cross-sectional study.

Although the platelet count may provide clues regarding the severity of liver disease, there are currently no available data supporting the utility of the platelet count to evaluate the degree of liver injury in patients with chronic hepatitis B virus (HBV) infection. The present study aimed to determine the association between the platelet count and the severity of liver injury in patients with chronic HBV infection. A total of 941 patients were included and were stratified into a Child-Turcotte-Pugh (CTP) class A group and a CTP class B/C group using the CTP scoring system. A total of 53 patients underwent liver biopsy. The pathological stage F4 was defined as cirrhosis based on the METAVIR scoring system. Compared with that in patients with CTP class A, the platelet count in patients with CTP class B/C was lower (P<0.001). Similarly, for patients with normal alanine aminotransferase (ALT) levels, the platelet count was significantly different between the CTP class B/C and A groups (P<0.001). The platelet count was inversely correlated with the CTP score (r=-0.420, P<0.001) and independently associated with CTP grade B/C [odds ratio (OR), 0.994; 95% CI, 0.990-0.999; P=0.009]. The area under the receiver operating characteristic curve (AUC) of the platelet count to distinguish CTP grade B/C from A was 0.712 and 0.791, respectively, in all patients with HBV infection and the subset with normal ALT levels. In addition, compared to patients with chronic hepatitis B, patients with cirrhosis had a lower platelet count and higher aspartate transaminase-to-platelet ratio index (APRI) and fibrosis index based on four factors (FIB-4) (P<0.001). The platelet count was inversely correlated with FIB-4 (r=-0.855, P<0.001) and APRI (r=-0.741, P<0.001). The AUC for the platelet count to distinguish cirrhosis from chronic hepatitis B was 0.927 (sensitivity, 78.76%; specificity, 92.22%). Among patients who underwent liver biopsy, the platelet count in those with F4 was lower compared with that in patients with ≤F3 (P=0.013). The platelet count was inversely correlated with the pathological stage (r=-0.295, P=0.032) and was independently associated with F4 (OR, 0.978; 95% CI, 0.960-0.997; P=0.026). The AUC of the platelet count to distinguish F4 from patients with ≤F3 was 0.761. In conclusion, the platelet count may be used as a non-invasive marker to assess the severity of liver injury and of liver fibrosis in patients with chronic HBV infection.

Insecticidal and repellent efficacy against stored-product insects of oxygenated monoterpenes and 2-dodecanone of the essential oil from Zanthoxylum planispinum var. dintanensis.

Essential oils (EOs) extracted from leaves (EL) and fruit pericarp (EFP) of Zanthoxylum planispinum var. dintanensis were analyzed for their chemical composition by GC-MS technique and evaluated for their fumigant, contact toxicity and repellency against three stored-product insects, namely Tribolium castaneum, Lasioderma serricorne, and Liposcelis bostrychophila adults. Results of GC-MS analysis manifested that EL and EFP of Z. planispinum var. dintanensis were mainly composed of oxygenated monoterpenes. Major components included linalool, sylvestrene and terpinen-4-ol. The obvious variation observed between two oil samples was that EL contained 2-dodecanone (11.52%) in addition to the above mentioned components, while this constituent was not detected in EFP. Bioassays of insecticidal and repellent activities were performed for EL, EFP as well as some of their individual compounds (linalool, terpinen-4-ol and 2-dodecanone). Testing results indicated that EL, EFP, linalool, terpinen-4-ol and 2-dodecanone exhibited potent insecticidal and repellent activities against the three target insects selected. Among the three individual compounds, 2-dodecanone was significantly toxic to T. castaneum (LD50 = 5.21 µg/adult), L. serricorne (LD50 = 2.54 µg/adult) and L. bostrychophila (LD50 = 23.41 µg/cm2) in contact assays and had beneficial repellent effects on L. serricorne at 2 and 4 h post-exposure. The anti-insect efficacy of Z. planispinum var. dintanensis EO suggests it has potential to be used as botanical insecticide or repellent to control pest damage in warehouses and grain stores.

Human umbilical cord mesenchymal stem cells inhibit proliferation of hepatic stellate cells in vitro.

The effect of human umbilical cord mesenchymal stem cells (hUC-MSCs) on the proliferation of hepatic stellate cells (HSCs) is largely unknown. The purpose of this study was to explore the mechanism of action of hUC­MSCs on the proliferation of HSCs in vitro. The upper and lower double-cell co-culture system was established between hUC­MSCs and HSCs in the experimental group. HSCs were cultured alone as a negative control group. Cell proliferation and apoptosis were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry, respectively. Cell supernatants were harvested to determine the concentration of transforming growth factor-ß1 (TGF-ß1) by ELISA. mRNA and protein of TGF-ß1, Smad3 and Smad7 in HSCs were determined by reverse transcription-polymerase chain reaction and western blotting, respectively. In the co-culture group, the proliferation of HSCs was significantly inhibited compared with the negative control group at 24 and 48 h (p<0.05). Apoptosis of HSCs in the co-culture group increased compared with that in the negative control group, which was more obvious at 48 h (p<0.05). The concentration of TGF-ß1 in the co-culture group was significantly lower than in the HSCs cultured alone (p<0.05). After HSCs were co-cultured with hUC­MSCs for 48 h, expression of TGF-ß1 and Smad3 mRNA and protein was reduced and expression of Smad7 mRNA and protein was increased compared with the negative control group (p<0.05). hUC­MSCs inhibited proliferation of HSCs, possibly through inhibiting TGF-ß1 and Smad3 expression and increasing Smad7 protein expression.

Research Advances in Molecular Mechanisms of the Invasion and Metastasis of Lung Cancer.

The basic way of invasion and metastasis of lung cancer is that the tumor cells shed in the extracellular matrix, invade the basement membrane and the surrounding tissue, infiltrate into blood flow, and then survive and transport via the blood flow. After having been extravasated, migrated and arrested in the distant site, they finally form a metastatic lesion. Some basic mechanisms are required in these steps, such as tumor stem cells, diffusion and activity of tumor cells, escaping from apoptosis, angiogenesis and lymphangiogenesis, infiltration into blood flow, circulation and exudation, and distant metastasis proliferation. A better understanding of the mechanisms of the invasion and metastasis of lung cancer will facilitate the prevention and treatment of lung cancer.

Bone marrow-derived mesenchymal stem cells inhibit the proliferation of hepatic stellate cells by inhibiting the transforming growth factor ß pathway.

Bone marrow-derived mesenchymal stem cells (BM-MSCs) are considered to be a potential therapy for end-stage liver disease. However, the therapeutic mechanism of BM-MSCs remains unclear. The aim of the current study was to investigate the role of paracrine signaling in BM­MSCs in liver cirrhosis in vitro. Human BM­MSCs and hepatic stellate cells (HSCs) were cultured using a vertical double cell co­culture system. Groups were divided into HSCs alone (control group) and the co­culture system of BM­MSCs with HSCs (experimental group). HSC morphology was observed by inverted phase contrast microscopy. The proliferative capacity of HSCs was measured with the MTT assay and flow cytometry. Hoechst staining was performed to examine the apoptosis of HSCs. Transforming growth factor (TGF)­ß1 and Smad7 mRNA expression were detected by reverse transcription­quantitative polymerase chain reaction and western blotting. BM­MSCs did not inhibit the proliferation of HSCs at 24 h, however significantly inhibited the proliferation of HSCs at 48 and 72 h. BM­MSCs additionally induced the apoptosis of HSCs at 48 h. The concentration of TGF­ß1 in the supernatant at 24 h and 48 h in the co­cultured system was observed to be significantly lower than in the control group (P<0.05). The level of TGF­ß1 mRNA in the experimental group at 48 h was significantly lower than the control group, however Smad7 mRNA levels were significantly greater than in the control group. Additionally, TGF­ß1 protein levels were significantly lower than in the control group, however levels of Smad7 were greater than the control group. It was concluded that BM­MSCs are able to inhibit the proliferation and promote the apoptosis of HSCs. In addition, the mechanism may be associated with inhibition of the TGF-ß1/Smad pathway in HSCs.

[Pro-angiogenic effects of four Chinese medicines and three herbal prescription in chicken chorioallantoic membrane model].

OBJECTIVE: To observe the pro-angiogenic effect of four Chinese medicines and three herbal prescriptions, screen the effective components from them. METHODS: Chicken chorioallantoic membrane (CAM) model was employed to observe the pro-angiogenic activities of Angelicae Sinensis Radix, Salviae Miltiorrhizae Radix, Notoginseng Radix, Astragali Radix, Xuefuzhuyu decoction, Dangguibuxue decoction and Taohongsiwu decoction, all of them were claimed to promote angiogenesis. The effective components were screened from the extracts. RESULTS: Compared with negative control group, the blood vessel densities in Angelicae Sinensis Radix and Notoginseng Radix groups were not increased significantly (P > 0.05). However, blood vessel densities in Astragali Radix group, Salviae Miltiorrhizae Radix group, Xuefuzhuyu decoction group, Dangguibuxue decoction group and Taohongsiwu decoction group were notably enhanced (P < 0.05). Dangguibuxue decoction showed a more than 90% of increase in blood vessel densities as compared with the negative control group (P < 0.01), and components contained ferulic acid and astragaloside from Dangguibuxue decoction displayed significantly pro-angiogenic effect (P < 0.05). CONCLUSION: Dangguibuxue decoction and its extract, components contained ferulic acid and astragaloside, can improve angiogenesis in CAM model significantly.

[Expression and significance of mRNA and protein of eIF4E, p-eIF4E and MCl-1 in pathological scar].

OBJECTIVE: To study the expression of eIF4E, p-eIF4E (Ser 209) and Mcl-1 gene in the pathological scars and to investigate its role and its probable mechanism in the pathogenesis of abnormal scar. METHODS: Quantitative real-time PCR and Western Blot was performed to detect the expression and distribution of mRNA and protein of eIF4E and Mcl-1 in hypertrophic scar (10 cases), keloid (10 cases), normal scar (10 cases), and normal skin (10 cases). Western Blot was performed to detect the expression and distribution of protein of p-eIF4E in hypertrophic scar (10 cases), keloid (10 cases), normal scar (10 cases), and normal skin (10 cases). RESULTS: The expression of eIF4E mRNA and protein were 1.38 +/- 0.45, 1.23 +/- 0.23 in the normal skin (10 cases); 5.400 +/- 0.450, 5.460 +/- 0.460 in normal scar (10 cases); 0.597 +/- 0.060, 0.590 +/- 0.040 in hypertrophic scar (10 cases) and 0.694 +/- 0.066, 0.697 +/- 0.022 in keloid (10 cases). The expression of p-eIF4E protein in the normal skin (10 cases), normal scar (10 cases), hypertrophic scar (10 cases), and keloid (10 cases) were 0.202 +/- 0.037, 0.216 +/- 0.019, 0.426 +/- 0.026, 0.433 +/- 0.027. The expression of Mcl-1 mRNA and protein were 1.510 +/- 0.660, 1.400 +/- 0.530 in the normal skin (10 cases); 6.65 +/- 0.85, 7.23 +/- 1.53 in normal scar (10 cases); 0.589 +/- 0.059, 0.660 +/- 0.063 in hypertrophic scar (10 cases) and 0.870 +/- 0.118, 0.914 +/- 0.064 in the keloid (10 cases). The positive rate of mRNA and protein of eIF4E and Mcl-1 was not statistically different between the hypertrophic scar and keloid (P > 0.05), while they were all remarkably significant between normal scar and abnormal scar (P < 0.05). The phosphorylation of eIF4E in pathological scar was higher than that in control group. In pathological scar, mRNA and protein of eIF4E and Mcl-1 showed a strong positive correlation. CONCLUSIONS: The result indicates that the expression of eIF4E, p-eIF4E and Mcl-1 is increased in pathological scar. eIF4E plays an important role in pathological scar. Its activity is regulated by its phosphorylation. Therefore, eIF4E, p-eIF4E and Mcl-1 overexpression may play an important role in the proliferation of fibroblasts and in the pathogenesis of pathological scar.

[Screening of the binding peptides of Mycobacterium tuberculosis H(37)Rv].

OBJECTIVE: To screen the Mycobacterium tuberculosis H(37)Rv binding peptide using phage-displayed random peptide libraries, and to analyze the binding capacity of the peptide with Mycobacterium tuberculosis. METHODS: Inactive Mycobacterium tuberculosis H(37)Rv was used for screening of the binding peptide from the Ph.D.-7 peptide library, and Mycobacterium smegmatis was used for reverse screening during the 2(nd) to 4(th) rounds of screening. After 4 rounds of screening, single phages were randomly selected for DNA sequencing. The selected clones were tested by indirect enzyme linked immunosorbent assay (ELISA). The peptide of positive clone, which showed the highest affinity, was synthesized in vitro with fluorescent markers. The specific combination of the peptide with 16 mycobacterium standard strains and 3 other microbes (Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans) were observed by fluorescence microscopy. RESULTS: After 4 rounds of biopanning, remarkable enrichment of the phages that specifically bind with target molecules were observed. Single phages were randomly selected for sequencing analysis and 5 sequences were obtained. Five phages with different sequences were detected using indirect ELISA and all of them were found to be positive clones. Phage 8 showed the highest affinity with target molecule. The peptide of phage H8 was synthesized in vitro with fluorescent markers, and it was confirmed that the peptide could bind with H(37)Rv and other 15 mycobacterium including Mycobacterium smegmatis, but not with 3 other microbes. CONCLUSIONS: By using phage-displayed random peptide libraries, we obtained the binding peptide of H(37)Rv. It was shown that the peptide could bind with Mycobacterium tuberculosis specifically, which provided a new way for the detection of Mycobacterium tuberculosis in vitro.

Selection and application of peptide mimotopes of MPT64 protein in Mycobacterium tuberculosis.

Antibody responses can be useful markers of tuberculosis (TB) infection, especially in the screening of extra-pulmonary TB. MPT64 is an important antigen in Mycobacterium tuberculosis (MTB) infection and is used in serological diagnosis. However, large variability in the diagnostic accuracy of MPT64 as a serological tool has limited its application. Phage-displayed random peptide libraries have emerged as a powerful technique to select peptides (epitopes) or mimotopes that may serve as surrogate diagnostic markers in serological tests. In the present study, this method was employed to identify mimotopes of the MPT64 protein of MTB by screening a linear heptapeptide library with rabbit antibodies raised against MPT64 protein. Two antigenic mimotopes (M2 and M6) resembling B-cell epitopes of MPT64 were identified that bound the affinity purified anti-MPT64 polyclonal antibodies and competed with MPT64 for antibody binding. From the results of sequence alignment and a structure modelling figure of MPT64, the sequence of the 2nd to 5th amino acids (DSML) of M2 was totally consistent with the sequence of the 224th to 227th amino acids of MPT64 and the peptide is located on the surface of the space structure of MPT64, suggesting that it might be a linear epitope of MPT64. The recognition of both phage-displayed and synthetic peptides of M2 by the anti-MPT64 polyclonal antibodies also supported this. Although no recurring sequence and no analogue to MPT64 of M6 were found for sequence alignment, the recognition of both phage-displayed and synthetic peptides of M6 by the anti-MPT64 polyclonal antibodies indicated that it might be a mimotope of a conformational epitope of MPT64. According to the results of the reactivity of human sera with synthetic M2 and M6 peptides and MPT64, M2 showed a significantly higher AUC and sensitivity than M6 and MPT64, especially for the sera from sputum-negative TB patients, suggesting that the M2 mimotope may be useful in serological diagnostic testing for TB.